Photographic diffusion transfer materials and processes utilizing balasted hydrazone compounds to release mobile acid dyes for transfer

ABSTRACT

In a color photographic diffusion transfer process are used diffusion-resistant dye-giving compounds, capable of forming diffusible acid dyes on reaction with oxidation products of black-and-white and color-forming developers and having the formula: WHEREIN R1 represents hydrogen, alkyl, aralkyl or amino; R2 represents alkyl, aralkyl, aryl, acyl or amino, or R1 and R2 together represent the ring members required to complete an isocyclic or heterocylic ring; X represents sulfonyl, carbonyl or a single chemical bond; A represents a radical rendering resistant to diffusion, and B represents a dye radical; or A represents a dye radical and B represents a radical rendering resistant to diffusion.

United States Patent Walter Pusehel Leverkusen;

Justus Danhauser; Karlhelnz Kabltzke; Paul Marx; Arnlried Melzer, all ofCologne; Karl-Wilhelm Sehranz, Opladen;

[72] Inventors Hans Vetter; Willibald Pelz, both of Cologne, all ofGermany [21] Appl. No. 41,078

[22] Filed May 27,1970

[45] Patented Dec. 21,197]

[73] Assignee Agfa-Gevaert Aktiengesellschaft Leverkusen, Germany [32]Priority June 13, 1969 [3 3 1 Germany [$4] PI'IOTOGRAPIIIC DIFFUSIONTRANSFER MATERIALS AND PROCESSES UTILIZING BALASTED HYDRAZONE COMPOUNDSTO RELEASE MOBILE ACID DYES FOR TRANSFER ll Claims, No Drawings [52] US.Cl 96/3, 96/29, 96/76 C, 96/99, 260/240 [51 Int. Cl G03c 7/00 [50] Fieldof Search 96/3, I00, 29 D, 9, 99

[56] References Cited 7 UNITED STATES PATENTS 3,443,940 5/1969 Bloom etal 96/3 Primary Examiner-Norman G. Torchin Assistant Examiner-AlfonsoSuro Pico Attorney-Connolly and Hutz ABSTRACT: In a color photographicdiffusion transfer process are used diffusion-resistant dye-givingcompounds, capable of forming diffusible acid dyes on reaction withoxidation products of black-and-white and color-forming developers andhaving the formula:

PIIO'IOGRAPHIC DIFFUSION TRANSFER MATERIALS AND PROCESSES UTILIZINGBALASTED IIYDRAZONE COMPOUNDS TO RELEASE MOBILE ACID DYES FOR TRANSFER APHOTOGRAPHIC DYE DIFFUSION TRANSFER PROCESS AND A CORRESPONDINGPHOTOGRAPI-IIC MATERIAL This invention relates to a photographic dyediffusion transfer process in which at least one silver halide emulsionlayer of a photosensitive material is exposed and developed to produce acolor image in which process a dye rendered diffusible throughdevelopment is transferred at least in part to form an image on areceiving layer. The invention also relates to a photosensitive materialfor carrying out this process.

It has long been known in black-and-white photography that to producedirect positive pictures and exposed silver halide emulsion layer can bedeveloped to form a negative silver image and that portion of the silverhalide which remains undeveloped can be transferred imagewise to areceiving layer where it is converted into a positive silver image, forexample by a precipitant. Efforts have been made to use these so-calledsilver salt diffusion processes in color photography. Usually, it isonly a diffusion of silver salts which occurs in this case, whereas thedye is formed in the receiving layer through chromogenic development.

Furthermore, diffusion processes for producing color photographicnegative or positive images are already known in which a color-formingcoupler or a preformed dye diffuses into an image-receiving layer.

In one conventional process, use is made of the fact that the dye formedduring chromogenic development is resistant to diffusion, while thecolor-fonning coupler from which it is formed and which in principle iscapable of diffusion by virtue of its average molecular weight, is soincorporated in the photosensitive layer in the form of oil packs," i.e.dissolved in droplets of a high-boiling low molecular weight organicsolvent substantially insoluble in water, as to be resistant todiffusion. This process is described, for example, in German Pat. Nos.1,150,278 and 1,272,716. Unfortunately, due both to the nature of thehydrophilizing groups required for diffusion and to the nature of thedevelopers used, it is necessary in this process to operate at anextremely high pH value in order to achieve diffusion of the couplers.This process gives azomethine dyes which have their conventionaldisadvantages, for example limited stability and inadequate resistanceto light.

In another conventional process, use is made of so-called dyedevelopers, i.e. compounds which contain in the same molecule a dyeradical and a group which is capable of developing silver halide. Thisprocess is described, for example, in German Pat. No. 1,196,075.Unfortunately, extremely complicated materials are required for carryingout this process. 1n addition, it is necessary in this case too tooperate at an extremely high pH value due to the nature of thediffusion-promoting hydrophilizing groups, usually phenolic hydroxylgroups.

In a third color photographic diffusion process which is described, forexample, in German Pat. No. 1,095,115 or in the corresponding US. Pat.No. 3,227,550, nondifiusing couplers are used in which case developmentwith color-forming developers is accompanied by the cleavage of a bondwhich through a linking members, links the per se diffusion-resistantcoupler radical with a per se diffusible dye radical or second couplerradical, or a radical rendering the molecule resistant to diffusion withthe per se diffusible coupler radical. Reference is made in theaforementioned patent specification to the couplers commonly used inphotography such as 5- pyrazolone derivatives, phenol and a-naptholderivatives and open-chain ketomethylene compounds. 1n the case of the5- pyrazolone compounds, the coupling position of the coupler moleculeis the carbon atom in the 4-position, in the case of the phenols anda-naphthols, similarly, the coupling position is the carbon atom in the4-position and in the case of the openchain ketomethylene couplers thecoupling position is the carbon atom of the methylene group in the group-CO-CH CO--.

During the coupling reaction of the couplers with oxidized color-formingdevelopers the substituent in the coupling posi tion is split off,resulting in the formation either of a diffusing azomethine dye or even,where the coupler portion is diffusion resistance, of a diffusing dyewhich may be of another type, depending on the way in which the processis carried out. The diffusible dyes formed diffuse out of thephotosensitive layer into an image-receiving layer being in intimatecontact with the photosensitive layer whereupon the dyes are anchored inthe receiving layer by mordanting.

The individual steps of this process have been known for someconsiderable time. For example, the process in which dyes diffuse toform an image is based on the Technicolor process. Reference is alsomade in this connection to Bela Gaspars imbibition process. It is alsoknown that the principle of splitting off radicals situated in thecoupling position of color-forming couplers can be used to form a colorimage. This can be seen, for example, from US. Pat. Nos. 2,435,616;2,453,661 and 2,455,169.

Although by combination of these individual steps an extremelyinteresting and technically advanced dye diffusion transfer process maybe obtained, this process is nevertheless attended by certaindisadvantages. For example, the diffusing dyes are usually azomethinedyes to which reference has already been made, and accordingly show onlya moderate stability and fastness to light. However, other seriousdisadvantages arise where dyes which can belong to a different class ofdyes and which hence can be more resistant to light, are split off fromthe coupling position of diffusion-resistant couplers in this process.

That portion of molecule to be split off in coupling through oxidationis attached to the coupling position through a connecting or linkageradical such as azo (-N=N azoxy mercury (Hg-), oxy (O), alkylidene(includes both CI-I- and =CI-I-), thio (S), or dithio (-S-S).Unfortunately, not all the proposed groups have proved to be of equaladvantage. For example, some of them, for example the groups -l-1g-, Oand CH, are not suitable for-use in practice because they are split offmuch tooslowly. 1n addition, it is only the azo bond that isspecifically disclosed in the corresponding patent literature, forexample in US. Pat. No. 3,227,550, as the cleavable bond betweenlight-fast dye and diffusion resistant coupler portion. If, however, theazo group is selected as the bridge member, the reaction with oxidizedcolor-forming developer is accompanied in the known manner by theformation of nitrogen which partly escapes from the layer in the form ofmicroscopic bubbles and interrupts the necessary contact between thedye-giving layer and the imagereceiving layer. This is particularly thecase where heating is used to accelerate the process.

Unfortunately, the thioether group which is as already known readilysplit off from the coupling position of couplers during the reactionwith oxidized color-forming developer, can only be used with certaindisadvantages as the bridge member between the diffusion-resistantcoupler and the diffusable dye radical in this dye-diffusion process.The reason for this is that it is know that mercaptans which are, ofcourse, formed during this reaction either react very readily withsilver halide to form silver mercaptides through a chemical reaction orare retained by the silver halide through adsorption. Use is made ofthis fact, for example, in cases where DlR couplers (developmentinhibitor releasing couplers) are used. Unfortunately, these propertiesrepresent an obstacle to the need for quick and quantitative diffusionof the dyes liberated.

The object of the present invention is to provide both a sim' pledye-diffusion process and a photographic material suitable for use inthis process which does not have any of the disadvantages affecting theprocesses referred to above.

A color photographic diffusion transfer process has now been found inwhich at least one silver halide emulsion layer of a photosensitivematerial is exposed and developed to form a color image and in which adye which has been rendered diffusible through development istransferred imagewise at least in part to a receiving layer, and whichis characterized by the fact that a compound of the following formula isincorporated in diffusion-fast form in the silver halide emulsion layeror in a layer adjacent thereto which compound is called dye-givingcompound" hereinafter:

in which R, represents hydrogen, an alkyl group with up to 20 carbonatoms and preferably with one to five carbon atoms, an aralkyl group forexample benzyl, an aryl group, for example pl'ienyl, an amino groupsubstituted by alkyl or aryl, for example phenyl, in which case twoalkyl groups on the nitrogen atom can be closed together to form a ring;R represents an alkyl group with up to 20 carbon atoms, an

aralkyl group, for example benzyl, an aryl group, for example phenyl, anacyl group derived from aliphatic carboxylic acids with up to 20 carbonatoms or aromatic carboxylic acids, for example benzoyl, an amino groupsubstituted by alkyl or aryl, for example phenyl, in which case twoalkyl groups on the nitrogen can be closed together to form a ring; or Rand R together represent the ring members required to complete apreferably 5- or 6-membered isocyclic or heterocyclic group with anoptionally anellated benzene ring; at least one of the radicals R and Rcontains the group A, X represents a sulfonyl group, a carbonyl group ora single chemical bond; A represents a photographically inert radicalrendering the dye-giving compound resistant to diffusion; and B is a dyeradical; or A represents a dye radical either on its own or togetherwith R and B represents a photographically inert radical rendering thedye-giving compound resistant to diffusion. in the present context,radicals rendering the dye-giving compounds resistant to diffusioninclude radicals of the kind which enable the compounds according to theinvention to be so incorporated in the hydrophilic colloidsconventionally used in color photographic materials, as to be resistantto diffusion. lt is preferred to use for this purpose organic radicalswhich may generally contain linear or branched aliphatic groups andoptionally also isocyclic or heterocyclic aromatic groups. The aliphaticportion of these radicals generally contains from eight to carbon atoms.These radicals are attached to the remaining portion of the moleculeeither directly or indirectly, for example, through one of the followinggroups: CONH-, SO NHl-, -CO-, -SO. NR- in which R represents hydrogen oralkyl, -O or -S-.

in addition, the radical rendering the dye-giving compounds resistant todiffusion may also contain water-solubilizing groups such as, forexample, sulfo groups or carboxyl groups which may also be present inthe anionic form. Since the diffusion properties are governed by themolecular size of the overall compound used, it is even sufficient incertain cases.

for example when the size of the total molecule used is great enough, touse shorter-chain radicals as the radicals rendering the dye-givingcompound resistant to diffusion.

Basically, the radicals of dyes of all classes may be used as the dyeradicals providing they are sufficiently diffusible after cleavage to beable to diffuse through the layers of the photosensitive material intothe image-receiving layer. On account of this requirement, the dyeradicals are preferably pr0- vided with at least one but generally witha plurality of watersolubilizing groups, Suitable water-solubilizinggroups include inter alia carboxyl groups, sulfo groups, hydroxyl groupsor hydroxy alkyl groups. The following are mentioned as examples of dyesparticularly suitable for use in the process according to the invention:azo dyes, anthraquinone dyes, phthalo cyanine dyes, indigo dyes andtriphenyl methane dyes.

The process according to the invention is distinguished from theprocesses referred to in the foregoing in regard inter alia to thecompounds used which do not contain any of the coupler radicals commonlyused in conventional color photography. Another feature whichdistinguishes the process according to the invention from conventionalprocesses is the relatively wide range of suitable developer substancesbecause the nuance of the dyes transferred is not determined by thechemi cal structure of the developer molecule.

The dyes split off from the dye-giving compounds according to theinvention during the reaction with developer oxidation products must besufficiently hydrophilic to enable quick and substantially quantitativediffusion to be obtained. The hydrophilic properties are usuallyimparted by sulfo groups or carboxyl groups. it is known from couplerchemistry that it is necessary to achieve a balance between the sizeofthe radicals rendering the dye-giving compounds resistant to diffusionand the number of solubilizing groups to ensure on the one hand adequateresistance to diffusion and on the other hand adequate solubility inaqueous-alkaline media. Thus, the greater the number of solubilizinggroups, the lower is the re sistance to diffusion. The larger the dyemolecular split off, the greater the number of solubilizing groupsrequired for diffusion.

Two requirements have to be satisfied in the dye diffusion transferprocess according to the invention. The dye-giving compounds accordingto the invention have to be embedded in the photosensitive layer or in alayer adjacent thereto so as to be completely resistant to diffusion,and the dyes liberated during the reaction with the developer oxidationproducts have to be highly soluble in the reaction media and diffusible.The dye radical of the dye-giving compound is usually very large so thatthe dye split off should be as hydrophilic as possible, ie shouldcontain as many solubilizing groups as possible, in order to obtain thenecessary diffusion rate. On the other hand, the resistance to diffusionof the dye-giving compounds used in accordance with the invention has tomeet the same requirements as in conventional chromogenic processes,that is to say these compounds should contain as few solubilizing groupsas possible so that they are optimally resistant to diffusion.Accordingly, it is desirable for solubilizing groups which remainconnected with the dye molecule and impart to it a certain additionalcapability of diffusion, to be formed during the cleavage reaction.

In one particularly preferred embodiment of the process according to theinvention, therefore, compounds so incorporated as to be resistant todiffusion are used, corresponding to the general formula:

in which R, and R are as defined above; at least one of the radicals R,and R contains the group BALL;

X, represents a sulfonyl group or a carbonyl group;

BALL represents a ballasting photographically inert radical renderingthe dye-giving compound resistant to diffusion; and

DYE is a dye radical.

in this embodiment, both the dye radical and the radical rendering thedye-giving compound resistant to diffusion contain solubilizing groups,preferably sulfo groups. Thus, by selecting both the number and theposition of the solubilizing groups, it is possible to adapt thediffusion resistance of the dye-giving compound and the diffusibilityand the ability of the diffusing dyes to be absorbed by the mordants ofthe receiving layer, to the particular practical requirements. Thus, ithas proved to be of particular advantage in this embodiment, forexample, when X represents a sulfonyl group, that it is also possible touse dye-giving compounds which do not contain any solubilizing groups orfewer than required for diffusion. An extremely high resistance todiffusion is obtained in this way. Nevertheless, the dye split off isable to diffuse because an additional water-solubilizing group whichremains in the dye molecule is formed from the sulfonyl group duringcleavage by the developer oxidation product. In this way, not only arethe dyes split off capable of diffusion, but also the starting compoundsare highly insoluble in the photosensitive layer and hence resistant todiffusion.

In this embodiment, R and R together preferably represent the ringmembers required to complete a heterocyclic group with a 5- or 6-membered heterocyclic ring, for example with the oxazoline, thiazoline,imidazoline, pyrrolidine, pyrroline, l,2-dihydropyridine,l,4-dihydropyridine, thiadiazoline, pyrazoline or traizoline ring whichrings can have benzene rings condensed thereto. The heterocyclic groupadvantageously contains at least one polar water-solubilizing group, forexample a sulfo group or earboxyl group, either directly or by way of asubstituent, for example by way of a short-chain alkyl group.Nevertheless, other combinations, for example R,= H and R aryl, are alsopossible. Dye preferably represents a light-resistant dye radical, forexample an azo dye radical, an anthraquinone dye radical or aphthalocyanine dye radical.

in another embodiment of the process according to the invention, acompound so incorporated as to be resistant to diffusion is used,corresponding to the formula:

in which:

R represents hydrogen, an alkyl group, preferably with one to fivecarbon atoms, for example methyl, ethyl, or propyl, an aralkyl group,for example benzyl, or an aryl group, for example phenyl;

R represents an aryl group, for example a phenyl group which can be partof the chromophoric system of the dye radical;

X represents a sulfonyl group, a carbonyl group or a single chemicalbond;

BALL represents a ballasting photographically inert radical renderingthe dye-giving compound resistant to diffusion; and

DYE represents a dye radical either on its own or together with R Inthis case, R preferably represents an aryl group, for example a phenylgroup, to which a dye radical is attached either directly or indirectly,or which itself represent part of the chromophoric system of such a dyeradical. ln this latter case, the aryl group can be linked in anyposition, for example in the 0-, m or p-position, through an azo groupto an isocyclic or heterocyclic aromatic group, for example to an arylgroup or to a S-pyrazolone group, and together with this group can thusform a dye.

The dye-giving compounds originally fixedly incorporated in the layerare split during the reaction with developer oxidation products, as aresult of which the dyes are released from their anchorage. Since theygenerally contain one or even several solubilizing groups, they are ableto diffuse into the image-receiving layer which is in intimate contactwith the photosensitive layers at least during the development andwherein they are fixed by means of the dye mordant. The radicalrendering the dye-giving compound resistant to diffusion remains behindin the emulsion layer.

Since no dye is reformed in any of the aforementioned embodiments andsince in addition no dye is destroyed as for example in the azo dyebleaching process, it is a unique feature of the dye diffusion transferprocess according to the invention that, following dye transfer, the twolayers, namely the emulsion layer and the image-receiving layer, havethe same color but in opposite gradation.

The following are examples of suitable dye-giving compounds:

. Color of transferred dye S 0-minu- Z] NI-I-N=C\ cyan CIJH (I)CII:i 11

l -SO3H 0011; 11038 Q l SO2ZI The dye-giving compounds originallyfixedly incorporated in the layer are split during the reaction withdeveloper oxidation products, as a result of which the dyes are releasedfrom their anchorage. Since they generally contain one or even severalsolubilizing groups, they are able to diffuse into the image-receivinglayer which is in intimate contact with the photosensitive layers atleast during the development and wherein they are fixed by means of thedye mordant. The radical rendering the dye-giving compound resistant todiffusion remains behind in the emulsion layer.

Since no dye is reformed in any of the aforementioned embodiments andsince in addition no dye is destroyed as for example in the azo dyebleaching process, it is a unique feature of the dye diffusion transferprocess according to the invention that, following dye transfer, the twolayers, namely the emulsion layer and the image-receiving layer, havethe same color but in opposite gradation.

The following are examples of suitable dye-giving compounds:

Coior 0f OH O CH;

cyan

OCH; OH

SO lI OCH: IIOriS--- H cyan transferred dye (3 oynn (36) magnum 7- TM]!30 (3)4) hluv-vlulm.

}V N Ci-Tn m cm i m Nil N (1H 2 N N SOJNQ red 02H ll but The dye-givingcompounds according to the invention can be prepared by methods knownfrom the literature. For example, the hydrazones of the carbonylcompounds, for example benzthiazolone hydrazones or benzaldehydehydrazones, can

be reacted with sulfonic acid halides such as sulfonic acid chlorides orsulfonic acid fluorides. However, the reverse procedure is alsopossible, in which case the carbonyl compounds are used as the startingmaterials and are reacted with hydrazines or carboxylic acid hydrazidesor sulthydrazides. In connection with the synthesis of the compoundsaccording to the invention, reference is made to S. Hunig, Angewandte 55Chemie, 80, 343 1968), and other literature references quoted therein.

The synthesis of a few compounds is described in the following by way ofillustration:

coarseness 1551551 50)! H2 (13112 S OgNa mm-Qmrr-ooQsom 75 5.7 Parts ofthe hydrazone of formula I are dissolved at 50 C. in 200 parts of waterand 40 parts of pyridine. 5.9 Parts of the dye of formula ll are thenintrod cm into the resulting solution over a period of 30 minutes, fterwhich the mixture 5 is heated to 90 C. and retained at this temperaturefor 40 minutes. After cooling, the mixture is clarified, 80 parts ofmethanol are added followed by the introduction of 2 l .5 parts ofsodium chloride. The mixture is stirred for minutes, the precipitatefiltered under suction and then poured with stirring into 100 parts ofacetone. 6.7 Parts of the sodium salt of the compound 32 are obtainedafter the residue has been suction-filtered and dried.

Compound I is prepared by methods known from the literature. The dye offormula ll is obtained as follows:

6.5 Parts of the dye of formula lll:

OCHz III prepared by the methods normally employed in azo,chemistry,

are dissolved in 150 parts of water. A solution of 3.65 parts of4-fluorosulfonyl benzoyl chloride (whose preparation is described in J.Org. Chem. 30, page 1498 (1965)) in parts I of acetone is then addeddropwise over a period of 30 minutes, ;during which a pH value of from6.5 to 7 is maintained by the 30 simultaneous dropwise addition of a 10percent soda solution.

The mixture is stirred for l hour at pH 8, after which 20 parts ofsodium chloride are added. It is then heated to 70 C. and, aftercooling, the precipitate is filtered under suction. The residue istriturated with acetone and filtered. 9 Parts of the 35 dye of formulall are obtained after drying.

Compound 87 (sodium salt) 2.9l g. (0.005 mol) of the sulfliydrazideprepared from the aforementioned compound ll and 3.81 g. (0.006 mol) ofmhexadecyloxy benzaldehyde are heated for 3 hours to 55 to 60 C. in ml.of anhydrous pyridine and 50 ml. of anhydrous dimethyl formamide, andafter cooling, precipitated with 600 ml. of a 20 percent NaCl solution.The precipitate is filtered under suction, washed with 20 ml. of waterand dried with acetone. The excess aldehyde is removed by washing with 5ether.

Yield: 3.96 g., corresponding to 86 percent of the theoretical yield.Compound 66 7.54 g. (0.024 mol) of the azo dye aldehyde of formula IVobtained from maminobenzaildehyde by diazotization and fcoupling with4-hydroxy phthalic acid IV 0 H CH0 l l 4.92 g. (0.06 mol) of sodiumacetate and 6.4 g. (0.02 mol) of j cetyl sulihydrazide aresuspended inml. of alcohol/water (1:1), and'the resulting suspension heated for 2hours to 60 C. It is then cooled to 15 C., filtered under suction,washed with acetone and ether and then dried.

Yield: 9.3 g. corresponding to 76.7 percent of the theoretical yield.

. Compound 49 7.54 g. (0.024 mol) of the aforementioned compound IV 4.92g. (0.06 mol) of sodium acetate, and 8.56 g. (0.02 mol) ofp-hexadecyloxy-o-sulfophenyl-hydrazine are heated for 1 .hour to 50 C.in 100 ml. of pyridine/water lzl cooled and Y 30 g. of ice added. Theexcess pyridine is buffered to a pH of 6 by the addition of 6 Nhydrochloric acid, as a result of which the hydrazone is precipitated.It is suction filtered and dried. The almost dry product is trituratedwith acetone, filtered under suction and washed with ether.

Yield: 10.0 g. corresponding to 67.! percent of the theoretical yield.

The materials required for carrying out the process according to theinvention basically consist of two elements, namely a photosensitivematerial containing at least one silver halide emulsion layer and atleast one of the dye-giving compounds according to the invention, and anonphotosensitive imagereceiving material which contains a dye mordantand which is intended to absorb the diffusing dye.

Conventional silver halide emulsions are suitable for the purposes ofthe invention. These emulsions may be based on silver halide, silverchloride, silver bromide or mixtures thereof, optionally with a smallsilver iodide content of up to mol percent.

Gelatin is preferably used as a binder for the photographic layers.However, it can be replaced at least in part by other natural orsynthetic binders. Suitable natural binders include, for example,alginic acid, and its derivatives such as its salts, esters or amides,cellulose derivatives such as carboxymethyl cellulose, alkyl cellulosessuch as hydroxy ethyl cellulose, starch or its derivatives such as itsethers or esters or carragenates. Suitable synthetic binders includepolyvinyl a1- coho], partially hydrolyzed polyvinyl acetate andpolyvinyl pyrrolidone.

The emulsions can also be chemically sensitized, for example by theaddition during chemical ripening of sulfur-containing compounds suchas, for example, allyl isothiocyanate, allyl thiourea and sodiumthiosulfate. Other suitable chemical sensitizers include reducingagents, for example the tin compounds described in Belgian Pat. Nos.493,464 or 568,687, also polyamines such as diethylenetriarnine, oraminomethane-sulfinic acid derivatives, for example those of the kinddescribed in Belgian Pat. No. 547,323.

Other suitable chemical sensitizers include noble metals or noble metalcompounds such as gold, platinum, palladium, iridium, ruthenium orrhodium. This method of chemical sensitization is described in thearticle by R. Koslowsky, Z. Wiss. Phot. 46, 65-72 1951 The emulsions canalso be sensitized with polyalkylene oxide derivatives, for example withpolyethylene oxide with an average molecular weight of from 1,000 to20,000, also with condensation products of alkylene oxides and aliphaticalcohols, glycols, cyclic dehydration products of hexitols, withalkyl-substituted phenols, aliphatic carboxylic acids aliphatic amines,aliphatic diamines and amides. The condensation products have amolecular weight of at least 700 and preferably in an excess of 1,000.in order to obtain special effects, these sensitizers can, of course, beused in combination as described in Belgian Pat. No. 537,278 and inBritish Pat. No. 727,982.

The emulsions can also be spectrally sensitized, for example with theusual monomethine or polymethine dyes such as cyanines, hemicyanines,streptocyanines, merocyanines, ox onoles, hemioxonoles, styryl dyes orother methine dyes which also can contain three or more nuclei, forexample, rhodacyanines or neocyanines. Sensitizers of this kind aredescribed in the book by F. M. Harmer The Cyanine Dyes and RelatedCompounds" 1967), lnterscience Publishers, John Wiley and Sons.

The emulsions can contain the usual stabilizers, for example homopolaror saltlike compounds of mercury with aromatic or heterocyclic rings,such as mercaptotriazoles, simple mercury salts, sulfonium mercurydouble salts and other mercury compounds. Other suitable stabilizersinclude azaindenes, preferably tetraor penta-azaindenes, especiallythose that are substituted by hydroxyl or amino groups. Compounds ofthis kind are described in the article by lBirr, Z. Wiss. Phot. 47, 2-58(1952). Other suitable stabilizers include inter alia heterocyclicmercapto compounds, for example phenyl mercapto tetrazole, quaternarybenzothiazole derivatives and benzotriazole.

The emulsions can be hardened in the conventional manner, for examplewith formaldehyde or with halogen-substituted aldehydes containing acarboxyl group, such as mu cobromid acid, diketones, methane sulfonicacid esters and dialdehydes.

The emulsions may be either conventional negative emulsions or evendirect positive emulsions, for example those of the kind which have ahigh sensitivity inside the silver halide grains, or even emulsionswhich function in accordance with the principle of solarization. Thechoice of the emulsions is governed by the purpose for which it isintended to use the end product. If, for example, it is intended toproduce a positive image from a positive original, for example from acolor transparency, direct positive emulsions would preferably be used.it is, of course, also possible to process a negative emulsion in areverse development to form a corresponding positive image.

in cases where colored images are required, it is possible to use amaterial in which the photosensitive material contains only onephotosensitive layer and, for example, only one of the dye-givingcompounds according to the invention. In general, however, aphotosensitive color photographic multilayer material with at leastthree separate silver halide emulsion layers of which, for example, oneis sensitive to red light, another to green light and a third to bluelight, will be used for the production of multicolor images. Each of theaforementioned photosensitive layers is in intimate contact with one ofthe dye-giving compounds according to the invention.

The intimate contact between the dye-giving compound and the silverhalide required to obtain the desired effect can be established byintroducing the dye-giving compounds from aqueous-alkaline solutionsinto the silver halide emulsion layers utilizing the water-solubilizinggroups present. However, the diffusion-resistant compounds can also beintroduced into the layers by any one of the conventional emu'|sification processes. These processes are described, for example, inBritish Pat. Nos. 791,219 and 1,099,414 to 1,099,417. In anotherembodiment, it may be desirable, for example, to incorporate thedye-giving compounds together with silver ha lide and optionallydeveloper substances in the layer in the form of so-calledmicrocapsules, in which case two or more differently sensitizedphotosensitive silver halide emulsions and the correspondingdiffusion-resistant compounds can also be combined in a single layer onthe lines of so-called mixed grain emulsions as described, for example,in U.S. Pat. No. 2,698,794. The diffusion-resistant dyes can beincorporated either in a photosensitive layer itself or in an adjacentlayer. For example, the red-sensitive layer is associated with a cyandye, the green-sensitive layer with a magenta dye and the bluesensitivelayer with a yellow dye. 1n addition, the multilayer material cancontain intermediate layers in which there are in corporated othersubstances such as, for example, filter dyes, white couplers orantioxidants in order to limit the activity of the developer oxidationproducts in each case to the photosensitive layer, wherein they areformed and the layers wherein the oxidation products are desired tobecome active. As already mentioned, the layers of the photosensitivematerial can also contain as a further additive developer substances,for example conventional color-forming developers of the pphenylenediamine type, and also other developers, for example hydroquinonecatechol, N-methyl aminophenol or phenidone. The developers may beembedded in the layer in the form of their free molecules or in the formof their salts. Since they should only exert their effect during theinitial stages of the actual development process, a diffusion-resistantanchorage of the developer substances in the layers should be obtainedif possible. Thus, the developers may be introduced into the layer, forexample, again in the form of the aforementioned packs. Anotherpossibility is to use developing agent precursors or so-called maskeddevelopers," i.e. developer derivatives which do not act independentlyas developers but liberate the actual developers, for example after acleavage or a dissociation reaction initiated by heat or by alkali.Masked developers of this kind and their use in photographic layers aredescribed, for example, in German Pat. No. 1,246,406, in GermanAuslegeschrift 1,019,560, in British Pat. Nos. 632,836; 691,815;783,887; 1,069,061 and 1,114,227 and in US. Pat. Nos. 3,243,294 and3,342,599.

The nonphotosensitive image-receiving material usually consists of anarbitrary layer support, for example a transparent film or a suitablepaper, for example a plastics-coated paper and a layer of binder whichrepresents the image-receiving layer and which contains a dye mordant inorder to fix the diffusing dyes.

Preferred mordants for acid dyes include long-chain quaternary ammoniumor phosphonium compounds or ternary sulfonium compounds, for example ofthe kind described in U.S. Pat. Nos. 3,27l,l47 and 3,271,]48, alsocertain metal salts and their hydroxides which form substantiallyinsoluble compounds with the acid dyes.

The dye mordants are dispersed in the receiving layer in one of theusual hydrophilic binders, for example in gelatin,

polyvinyl-pyrrolidone, completely or partially hydrolyzed celluloseesters. Some binders can, of course, also function as mordants,especially those of the kind which represents polymers ofnitrogen-containing quaternary bases, for example polymers ofN-methyl-Z-vinyl pyridine of the kind described, for example, in U.S.Pat. No. 2,484,430, or polymers of aminoquanidine derivatives of alkylvinyl ketones of the kind described, for example, in U.S. Pat. No.2,882,l 56. However, other binders, for example gelatines, will usuallyhe added to the last of these mordant binders.

In order to obtain multicolored images by the process according to theinvention, thephotosensitive material is initially immersed briefly in adeveloper solution following exposure behind a colored original, andthen brought into effective contact with the nonphotoscnsitive receivingmaterial which has also been impregnated with a developer solution.Silver halide is reduced at the exposed areas. The developer oxidationproduct formed splits the dye-giving compounds according to theinvention and the dyes which have thus been rendered diffusible diffuseimagewise into the receiving layer where they are anchored by themordant.

in the present context, effective contact means that the dye split offis able to diffuse between the photosensitive material and theimage-receiving material. This does not necessarily mean that the layersof the photosensitive material containing the dye-giving compoundsaccording to the invention and the image-receiving layer cannot beseparated from one another by further colloid layers providing this doesnot prevent the dyes split off from diffusing.

In another embodiment of the process, the two elements may be arrangedone above the other on the same layer sup port. in this case, the layersupport initially carries the imagerecciving layer containing a dyemordant and a binder, and above the image-receiving layer the variouslayers of the photosensitive material. The photosensitive layers arewashed off following exposure and development and after the dyes whichhave been liberated imagewise by development have diffused into thelowermost image-receiving layer. In this case, readily solubleemulsions, for example of the kind based on polyvinyl alcohol oralkali-soluble cellulose ether phthalate, are generally used.

The liquid or pasty mixtures required to initiate the developmentprocess can, of course, also be accommodated in breakable containers orin rupturable pods that are split open under moderate mechanicalpressure, and can be arranged, for example, between the photosensitivematerial and the nonphotosensitive image-receiving layer as described,for example, in U.S. Pat. Nos. 2,698,244; 2,559,643; 2,647,049;

2,661,293; 2,698,798 and 2,774,668. A composite material ofp-phenylene-diamine type. Suitable color-forming developers are forexample N,N-dimethyl-p-phenylenediamine, N,N-diethyl-p-phenylenediamine, monomethyl-p-phenylenediamine2-amino-5-diethyl-aminotoluene,N-hutyl-N-wsulfobutyl-p-phenylenediamine,Z-amino-S-(N-ethyl-N-fimethanesulfonamidoethylamino)-toluene,Methyl-N43- hydroxyethyl-p-phenylene-diamine,N,N-bis-(B-hydroxyethyl)-p-phenylenediamine orZ-amino-S-(N-ethyl-N-[ihydroxyethylamino)-toluene. Other suitablecolor-forming developers are described, for example, in .I. Am. Chem.Soc. 73, 3,000 I I However, one particular advantage of the processaccording to the invention is that the range of developer substances isnot confined solely to the usual color-forming developers, insteadblack-and-white developers such as, for example, 4- aminophenol,4-methyl aminophenol, Lmethylaminophenol or 3-methyl-4-aminophenol, canalso be used for development. According to a preferred embodiment of theinvention eatechol and derivatives thereof can be used as developingsubstances, for example, eatechol, 4-cyclohexylcatechol, 3-methoxycatechol, 4-(N-octadecoylamino)-catechol or 5-dodecoylamino-benzodioxolone-(2).

The baths normally used in conventional development processes, forexample in color photography, can be used as developing baths in theprocess according to the invention. It is also possible however, toestablish the prerequisites for optimum diffusion by varying the mineralsalt content of the baths, the pH value, the viscosity and by addingorganic solvents. As a rule, any competent expert need only conduct afew routine preliminary tests for this purpose.

EXAMPLE I A color photographic multiple-layer material is prepared asdescribed in the following passage.

The layers mentioned in the following are cast in the order in whichthey are identified on to a layer support of pigmented cellulosetriacetate. I 1

l. A red-sensitive layerwhich, for 500 g. of an iodide-containing silverbromide emulsion (50 g. of silver per kg. of emulsion of which 4 molpercent are in the iodide form), contains 12 mg. ofa red-sensitizer ofthe formula:

which sensitizer has been mentioned in example ll of the GermanAuslegeschrift 1,213,240, 0.4 g. of saponin, 0.25 g. of N, N,N-tris-acryloyl hexahydro-l,3,5-triazine as hardener and 5 g. ofcompound 2. Silver coating approximately 0.9 g./m.

2. An intermediate layer ofa 2 percent gelatin solution.

3. A green-sensitive layer which, for 500 g. of the iodidecontainingsilver bromide emulsion described in l, contains l5 mg. of agreen-sensitizer of the formula which sensitizer has been described asdye No. 9 in Germ an Auslegeschrift 1,177,481, 0.53 g. of saponin aswetting agent, 0.25 g. of N, N, N"-tris-acryloyl hexahydrol ,3,5-triazine and 6 g. of compound 1 1. Silver coating approximately 1 g./m.

4. An intermediate layer ofa 2 percent gelatin solution.

5. An unsensitized blue-sensitive emulsion layer which, for 500 g. ofthe iodide-containing silver bromide: emulsion, described in 1, contains0.3 g. ofsaponin, 0.25 g. ofN, N, N"-tris-acryloyl hexahydro-l,3,5-triazine and 6 g. of compound 32. Silver coating approximately 0.9g./m."

6. A protective layer ofa 2.5 percent gelatin solution.

The photographic material is exposed behind colored originals and thenprocessed as follows: The material is immersed for 45 seconds in adeveloper of the following composition:

g. of N,N-diethyl-p-phenylene diamine,

0.5 g. of potassium bromide,

l g. of anhydrous sulfite,

25 g. of potassium carbonate, made up with water to 1 liter, and the pHvalue adjusted to l l with sodium hydroxide.

The photographic material is then brought into contact with animage-receiving layer which has also been immersed in the developer for45 seconds. The image-receiving layer consists of a pigmented cellulosetriacetate support, onto which the following layer is cast in athickness of from 5 to 8a: a gelatin layer containing 20 g. of polyvinylpyridine per kg. of percent aqueous gelatin solution.

After the two materials have been left in contact for 6 minutes, theyare separated and the image-receiving material rinsed thoroughly withwater for 3 minutes and then dried. A full color negative of theoriginal with a maximum density of around 2 is obtained.

EXAMPLE 2 Similar good results are obtained. if the material asdescribed in example 1 is treated with one of the following developers:A.

3 g. of catechol 0.3 g. of potassium bromide 25 g. of potassiumcarbonate 0.5 g. of anhydrous sodium sulfite 1 g. of ascorbic acid waterup to 1,000 ml. pl-l adjusted to 12. B. In the developer A catechol isreplaced by 3 g. of 4- cyclohexylcatechol. C.

3 g. ofcatechol 0.05 g. of l-phenyl-3-pyrazolidone 0.3 g. of potassiumbromide 25 g. of potassium carbonate 0.5 g. of anhydrous sodium sulfite1 g. of ascorbic acid water up to 1,000 ml. pH adjusted to 12. D.

10 g. of 2-amino-5-(N-butyl-N-hydroxyethylamino)-toluene (salt ofnaphthalene-l ,5disulfonic acid) 0.5 g. of potassium bromide 1 g. ofanhydrous sodium sulfite 25 g. of potassium carbonate water up to 1,000ml. pH adjusted to l 1. E. In the developer D the developing agentmentioned is replaced by 5 g. of2-amino-5-(N'ethyl-N-hydroxycthylaminol-toluene H 80 F. In the developerD the developing agent mentioned is replaced by g. of2-amino-5-(N-ethyl-N-B-methanesulfonairnidoethylamino)-toluenc-sulfate.G. In the developer A catechol is replaced by 5 g. of 3-methoxycatechol.

EXAMPLE 3 A color photographic multilayer material is prepared asdescribed in the following.

5 The following layers are successively cast on to a layer sup port ofwhite-pigmented cellulose triacetate:

1. A gelatin layer which. per kg. of 5 percent aqueous gelatin solutioncontains 30 g. of trimethyl octadecyl ammonium sulfate, 0.4 g. ofsaponin and 0.3 g. of N,N.N"- tris-acryloyl hexahydro-l,3,5-triazinc ashardener. This layer is cast in a thickness of 8a.

2. A sodium alginate layer approximately 1.0;; thick.

A green-sensitized layer similar to layer 3 of example 1 which contains0.3 g. of saponin, 0.25 g. of N,N,N trisacryloyl hexahydro-l,3,5-triazine as hardener and 6 g. of

the compound 34. Silver coating 0.9 g./m.

4. An intermediate layer of a 2 percent aqueous gelatin solution.

5. A red-sensitized layer similar to layer 1 of example 1 which contains0.4 g. of saponin, 0.25 g. of N,N,N"-trisacryloylhexahydro-1,3,5-triazine and 6 g. of the compound 2. Silver coating 0.8g./m.

6. An intermediate layer of a 2 percent aqueous gelatin solution.

7. An unsensitized blue-sensitive emulsion layer which, for

500 g. of the iodide-containing silver bromide emulsion described in lof example 1, contains 0.2 g. of saponin, 0.25 g. ofN,N',N"-tris-acryloyl hexahydro-l ,3,5-triazine as hardener and 7 g. ofcompound 12. Silver coating approximately 0.8 g./m.

. A protective layer of a 2.5 aqueous gelatin solution to which theusual hardeners and wetting agents have been added.

The color photographic material is exposed behind a mul ticoloredoriginal and processed as follows:

The material is immersed for 30 seconds in a developer of the followingcomposition:

10 g. of N-ethyl-N-w-hydroxyethylp-phenylene diamine,

0.8 g. of potassium bromide,

g. of potassium carbonate,

0.5 g. of anhydrous sodium sulfite, and

I g. of hydroxyethyl cellulose made up with water to 1 liter. The pH isadjusted to 1 l with sodium hydroxide.

The material is then removed from the developer. After a contact time of2 minutes, the developer and the emulsion layers are removed withconcentrated jet of water. A full colored negative of the original withbrilliant colors and deep blacks is obtained after drying.

EXAMPLE 4 A green-sensitized silver bromoiodide emulsion which containsper kg. 48 g. of silver and thereof 4 mol percent in the iodide form andto which have been added per kg. 15 g. of dye-giving compound 17, and 8g. of 4-(N-octadecoylaminolcatechol is coated on to a layer supportol'cellulose triacetate. Silver coating 1,3 g. per m.

This material is exposed behind a green step wedge and is the immersedfor 30 seconds in an activator bath ofthe following composition:

1.5 g. ascorbic acid 0.5 g. of potassium bromide 0.03 g. ofl-phcnyl-3-pyrazolidone 20 g. of potassium carbonate water up to 1,000ml. pH adjusted to 11.

The material is then brought into contact with an imagereceivingmaterial which consists of a layer support of cellulose triacctate on towhich has been coated a 10 percent aqueous gelatin solution containingper kg. 35 kg. of trimethyl octadecyl ammonium sulfate; layer thickness411..

After the two materials have been left in contact for 3 minutes they areseparated. A negative wedge is obtained in the image-receiving layerhaving a maximum density of 1.55 and a minimum density of 0. l 3.

EXAMPLE in the material of example 4 the derivative of catechol used isreplaced by 12 g. of the compound of the formula:

A solution of the following composition is used as activator: 0.8 g. ofanhydrous sodium sulfite 0.5 g. of potassium bromide 0.03 g. ofl-phenyl-3-pyrazolidone 25 g. of potassium carbonate water up to l,000ml. pH adjusted to 12. After processing a magenta wedge is obtainedhaving a maximum density of 1.2 and a minimum density of0.2.

EXAMPLE 6 A 10 percent aqueous gelation solution which contains per kg.20 g. of dye-giving compound 34 and mg. of silver sulfide is coated ontoa'layer support of cellulose triacetate; layer thickness l.8p.. As asecond layer is coated thereon a greensensitive silver bromoiodideemulsion, which contains per kg. 64 g. of silver and 4 mol percentthereof in the form of iodide; silver coating 1.6 g. per m.

After exposing behind a green step wedge, the material s dipped for 30seconds into a developing mixture of the following composition:

10 g. of N-ethyl-N-hydroxyethyl-p-phenylene-diaminc 0.5 g. of anhydroussodium sulfite 0.5 g. of sodium thiosulfate 0.5 g. of potassium bromideg. of potassium carbonate water up to 1,000 ml. pH adjusted to 11.6.

Then the material is brought into contact for 3 minutes with aimage-receiving material as described in example 4. After separation ofthe two materials a positive magenta wedge is obtained in theimage-receiving material having a maximum density of 1.38 and a minimumdensity of 0.23.

We claim:

1. A color photographic diffusion transfer process for the production ofcolor images, which comprises forming a pattern of developable silverhalide in a light-sensitive photographic material comprising at leastone silver halide emulsion layer and having distributed therein or in anadjacent layer a dye-giving compound being resistant to diffusion duringdevelopment in the presence of an alkaline developing solution, capableof forming a diffusible acid dye on reaction with developer oxidationproducts and having the formula:

in which R, represents hydrogen, alkyl with up to 20 carbon atoms, arylor amino substituted by alkyl or aryl, in which case two alkyl groups onthe nitrogen can be closed together to form a ring; R represents alkylwith up to 20 carbon atoms, aryl, acyl derived from an aliphaticcarboxylic acid with up to 20 carbon atoms or an aromatic carboxylicacid, or amino substituted by alkyl or aryl, in which case two alkylgroups on the nitrogen can be closed together to form a ring; or R, andR together represent the ring members required to complete an isocyclicor heterocyclic group; at least one of the radicals R, and R., carriesthe group A; X represents a sulfonyl group, a carbonyl group or a singlechemical bond; A represents a photographically inert radical renderingthe dye-giving compound resistant to diffusion; and B represents a dyeradical; or A represents a dye radical either on its own or inconjunction with R and B represents a photographically inert radicalrendering the dye-giving compound resistant to diffusion; treating saidmaterial with an alkaline developing solution in the presence of adeveloping agent and developing said pattern of developable silverhalide, said dye-giving compound reacting with the oxidation product ofthe developing agent during the development and thereby releasing adiffusible acid dye image in the area of development, during the courseof said development said dye image being transferred by diffusion whollyor in part to an image-receiving layercontaining a basic mordant foracid dyes.

2. A color photographic diffusion transfer process as claimed in claim1, wherein as dye-giving compound a compound of the following generalformula is used:

n A LL--E-- in which:

R, represents hydrogen, alkyl with up to 20 carbon atoms. aryl or aminosubstituted by alkyl or aryl, in which case two alkyl groups on thenitrogen can be closed together to form a ring;

R represents alkyl with up to 20 carbon atoms, aryl, acyl derived fromaliphatic carboxylic acids with up to 20 carbon atoms or aromaticcarboxylic acids, or amino substituted by alkyl or aryl, in which casetwo alkyl groups on' the nitrogen can be closed together to form a ring;or

R, and R together represent the ring members required to complete anisocyclic or heterocylic ring; at least one of the radicals R, and Rcarries the group BALL;

X, represents a sulfonyl group or a carbonyl group;

BALL represents a ballasting photographically inert radical renderingthe dye-giving compound resistant to diffusion; and

DYE represents a dye radical.

3. A color photographic diffusion transfer process as claimed in claim1, wherein as dye-giving compound a compound of the following generalformula is used:

R represents hydrogen, alkyl or aryl.

R represents an aryl group which can be part of th chromophoric systemof the dye radical;

X represents a sulfonyl group, a carbonyl group or a single chemicalbond;

BALL represents a ballasting photographically inert radical renderingthe dye-giving compound resistant to diffusion; and

DYE represents a dye radical either on its own or together with R,.

4. A color photographic diffusion transfer process for the production ofcolor images, which comprises exposing to a visible subject alight-sensitive photographic material compris ing superposed red, green,and blue light-sensitive silver halide emulsion layers and havingdistributed therein or in layers adjacent thereto dye-giving compoundsbeing resistant to diffusion during the development in the presence ofan alkaline developing solution, capable of forming a cyan, magenta, andyellow diffusible acid dye on reaction with developer oxidation productsand having the formula:

in which R, represents hydrogen, alkyl with up to carbon atoms, aryl oramino substituted by alkyl or aryl, in which case two alkyl groups onthe nitrogen can be closed together to form a ring;

R represents alkyl with up to 20 carbon atoms, aryl, acyl derived froman aliphatic carboxylic acid with up to 20 carbon atoms or an aromaticcarboxylic acid, or amino substituted by alkyl or aryl, in which casetwo alkyl groups on the nitrogen can be closed together to form a ring;or

R, and R, together represent the ring members required to complete anisocyclic or heterocylic group; at least one of the radicals R, and R,carries the group .A;

X represents a sulfonyl group, a carbonyl group or a single chemicalbond;

A represents a photographically inert radical rendering the dye-givingcompound resistant to diffusion; and

B represents a dye radical; or

A represents a dye radical either on its own or in conjunction with Rand B represents a photographically inert radical rendering thedye-giving compound resistant to diffusion;

treating said material with an alkaline developing solution in thepresence of a developing agent and developing said imagewise exposedmaterial, said dye-giving compounds reacting with the oxidation productof the developing agent during the development and thereby releasingeach a cyan, magenta and yellow diffusible acid dye image in the areasof development, during the course of said development said dye imagesbeing transferred by diffusion wholly or in part imagewise in registerto an image-receiving layer containing a basic mordant for acid dyes.

5. A process as claimed in claim 4 wherein, after the beginning ofdevelopment, the photosensitive material is brought into intimatecontact with the image-receiving layer and is separated from it againafter the dye images have been transferred to form a color image in saidimage-receiving layer:

6. A process as claimed in claim 4, wherein, before the beginning ofdevelopment, the photosensitive material is in intimate contact with theimage-receiving layer and is separated from it after the dye imagesformed by development have been transferred to form a color image insaid image-receiving layer.

7. A process as claimed in claim 4, wherein development is carried outby an alkaline liquid or viscous developer or activator solution in thepresence of a developing agent containproducts and having the formula:

in which R, represents hydrogen, alkyl with up to 20 carbon atoms, arylor amino substituted by alkyl or aryl, in which case two alkyl groups onthe nitrogen can be closed together to form a ring;

R represents alkyl with up to 20 carbon atoms, aryl, acyl derived froman aliphatic carboxylic acid with up to 20 carbon atoms or an aromaticcarboxylic acid, or amino substituted by alkyl or aryl, in which casetwo alkyl groups on the nitrogen can be closed together to form a ring;or

R and R, together represent the ring members required to complete anisocyclic or heterocyclic group; at least one of the radicals R and R,carries the group A;

X represents a sulfonyl group, a carbonyl group or a single chemicalbond;

A represents a photographically inert radical rendering the dye-givingcompound resistant to diffusion; and

B represents a dye radical; or

A represents a dye radical either on its own or in conjunction with R,;and

B represents a photographically inert radical rendering the dye-givingcompound resistant to diffusion;

10. A color photographic material is claimed in claim 9 which containsas dye-giving compound a compound of the following general formula:

in this formula:

R, represents hydrogen, alkyl with up to 20 carbon atoms, aryl or aminosubstituted by alkyl or aryl, in which case two alkyl groups on thenitrogen can be closed together to form a ring;

R represents alkyl with up to 20 carbon atoms, aryl, acyl derived fromaliphatic carboxylic acids with up to 20 carbon atoms or aromaticcarboxylic acids, or amino substituted by alkyl or aryl, in which casetwo alkyl groups on the nitrogen can be closed together to form a ring;or

R and R together represent the ring members required to complete anisocyclic or heterocyclic group; at least one of the radicals R, and Rcontains the group BALL;

X represents a sulfonyl group or carbonyl group;

BALL represents a ballasting photographically inert radical renderingthe dye-giving compound resistant to diffusion; and

DYE represents a dye radical,

II. A color photographic material as claimed in claim 9,

which contains as dye-giving compound a compound of the followinggeneral formula:

in this formula R represents hydrogen, alkyl or aryl;

R represents an aryl group which can be part of the chromophoric systemof the dye radical;

X represents a sulfonyl group, a carbonyl group or a single chemicalbond;

BALL represents a ballasting photographically incrt radical renderingthe dye-giving compound resistant to diffusion; and

DYE represents a dye radical either on its own or together with R gggUNITED STATES PATENT OFFICE CETIFICATE 0F CORECTWN Patent, 3, ,952 DatedDecember 21, 1971 Walter Puschel et al Inventor(s) It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 7, compound 9, right hand part of. formula should read 1 asfollows:

-- @ao z Column 8, compound 16, the middle part of the formula shouldread as follows:

oH 3 Column 9, compound 18, the right side of the formula should read asfollows:

Column 9, compound 19, left side of the formula should read as followsColumn 10, compound 27, left side of the formula should read. asfollows:

-- HO3S-/ Patent No, 3,628,952 I Dated December 21, 1971 InventorsWalter Puschel et al Column 12, compound 36, the right side of theformula should read as follows:

Column 12 comp 37 the right side of the formula should read as follows:

Column 13, compound #8, thehleft side of the formula should read asfollows:

-- Z3-NH-H=CH- Column 18, bottom formula, the left side should. read asfollows:

- Z HO S- Column 21, compound 103, right side of formula should read asfollows:

Patent No. 3,628,952 Dated December 21, 1971 Inventors Walter Puschel etal Column 29, in Example 5, the right side of the formula should read asfollows:

NH-CO-(CH -CH Column 6, lines #3 61, the text therein is a reiterationof the top of column 6 and should be deleted.

Signed and sealed this 10th day of April 1973.

(SEAL) Attest:

ROBERT GOTTSCHALK Commissioner of Patents EDWARD M.PLETCHER,JR.Attesting Officer

2. A color photographic diffusion transfer process as claimed in claim1, wherein as dye-giving compound a compound of the following generalformula is used: in which: R1 repResents hydrogen, alkyl with up to 20carbon atoms, aryl or amino substituted by alkyl or aryl, in which casetwo alkyl groups on the nitrogen can be closed together to form a ring;R2 represents alkyl with up to 20 carbon atoms, aryl, acyl derived fromaliphatic carboxylic acids with up to 20 carbon atoms or aromaticcarboxylic acids, or amino substituted by alkyl or aryl, in which casetwo alkyl groups on the nitrogen can be closed together to form a ring;or R1 and R2 together represent the ring members required to complete anisocyclic or heterocylic ring; at least one of the radicals R1 and R2carries the group BALL; X1 represents a sulfonyl group or a carbonylgroup; BALL represents a ballasting photographically inert radicalrendering the dye-giving compound resistant to diffusion; and DYErepresents a dye radical.
 3. A color photographic diffusion transferprocess as claimed in claim 1, wherein as dye-giving compound a compoundof the following general formula is used: in which R3 representshydrogen, alkyl or aryl. R4 represents an aryl group which can be partof the chromophoric system of the dye radical; X represents a sulfonylgroup, a carbonyl group or a single chemical bond; BALL represents aballasting photographically inert radical rendering the dye-givingcompound resistant to diffusion; and DYE represents a dye radical eitheron its own or together with R4.
 4. A color photographic diffusiontransfer process for the production of color images, which comprisesexposing to a visible subject a light-sensitive photographic materialcomprising superposed red, green, and blue light-sensitive silver halideemulsion layers and having distributed therein or in layers adjacentthereto dye-giving compounds being resistant to diffusion during thedevelopment in the presence of an alkaline developing solution, capableof forming a cyan, magenta, and yellow diffusible acid dye on reactionwith developer oxidation products and having the formula: in which R1represents hydrogen, alkyl with up to 20 carbon atoms, aryl or aminosubstituted by alkyl or aryl, in which case two alkyl groups on thenitrogen can be closed together to form a ring; R2 represents alkyl withup to 20 carbon atoms, aryl, acyl derived from an aliphatic carboxylicacid with up to 20 carbon atoms or an aromatic carboxylic acid, or aminosubstituted by alkyl or aryl, in which case two alkyl groups on thenitrogen can be closed together to form a ring; or R1 and R2 togetherrepresent the ring members required to complete an isocyclic orheterocylic group; at least one of the radicals R1 and R2 carries thegroup A; X represents a sulfonyl group, a carbonyl group or a singlechemical bond; A represents a photographically inert radical renderingthe dye-giving compound resistant to diffusion; and B represents a dyeradical; or A represents a dye radical either on its own or inconjunction with R2; and B represents a photographically inert radicalrendering the dye-giving compound resistant to diffusion; treating saidmaterial with an alkaline developing solution in the presence of adeveloping agent and developing said imagewise exposed material, saiddye-giving compounds reacting with the oxidation product of thedeveloping agent during the development and thereby releasing each acyan, magenta and yellow diffusible acid dye image in the areas ofdevelopment, during the course of said development said dye images beingtransferred by diffusion wholly or in part imagewise in register to animage-receiving layer containing a basic mordant for acid dyes.
 5. Aprocess as claimed in claim 4 wherein, after the beginning ofdevelopMent, the photosensitive material is brought into intimatecontact with the image-receiving layer and is separated from it againafter the dye images have been transferred to form a color image in saidimage-receiving layer.
 6. A process as claimed in claim 4, wherein,before the beginning of development, the photosensitive material is inintimate contact with the image-receiving layer and is separated from itafter the dye images formed by development have been transferred to forma color image in said image-receiving layer.
 7. A process as claimed inclaim 4, wherein development is carried out by an alkaline liquid orviscous developer or activator solution in the presence of a developingagent containing a primary amino group.
 8. A process as claimed in claim4, wherein development is carried out by an alkaline liquid as viscousdeveloper or activator solution in the presence of catechol or aderivative of catechol as developing agent.
 9. A light-sensitive colorphotographic material comprising at least one silver halide emulsionlayer and containing distributed therein or in a layer adjacent theretoa dye-giving compound being resistant to diffusion during development inthe presence of an alkaline developing solution, capable of forming adiffusible dye on reaction with developer oxidation products and havingthe formula: in which R1 represents hydrogen, alkyl with up to 20 carbonatoms, aryl or amino substituted by alkyl or aryl, in which case twoalkyl groups on the nitrogen can be closed together to form a ring; R2represents alkyl with up to 20 carbon atoms, aryl, acyl derived from analiphatic carboxylic acid with up to 20 carbon atoms or an aromaticcarboxylic acid, or amino substituted by alkyl or aryl, in which casetwo alkyl groups on the nitrogen can be closed together to form a ring;or R1 and R2 together represent the ring members required to complete anisocyclic or heterocyclic group; at least one of the radicals R1 and R2carries the group A; X represents a sulfonyl group, a carbonyl group ora single chemical bond; A represents a photographically inert radicalrendering the dye-giving compound resistant to diffusion; and Brepresents a dye radical; or A represents a dye radical either on itsown or in conjunction with R2; and B represents a photographically inertradical rendering the dye-giving compound resistant to diffusion;
 10. Acolor photographic material is claimed in claim 9 which contains asdye-giving compound a compound of the following general formula: in thisformula: R1 represents hydrogen, alkyl with up to 20 carbon atoms, arylor amino substituted by alkyl or aryl, in which case two alkyl groups onthe nitrogen can be closed together to form a ring; R2 represents alkylwith up to 20 carbon atoms, aryl, acyl derived from aliphatic carboxylicacids with up to 20 carbon atoms or aromatic carboxylic acids, or aminosubstituted by alkyl or aryl, in which case two alkyl groups on thenitrogen can be closed together to form a ring; or R1 and R2 togetherrepresent the ring members required to complete an isocyclic orheterocyclic group; at least one of the radicals R1 and R2 contains thegroup BALL; X1 represents a sulfonyl group or carbonyl group; BALLrepresents a ballasting photographically inert radical rendering thedye-giving compound resistant to diffusion; and DYE represents a dyeradical.
 11. A color photographic material as claimed in claim 9, whichcontains as dye-giving compound a compound of the following generalformula: in this formula R3 represents hydrogen, alkyl or aryl; R4represents an aryl group which Can be part of the chromophoric system ofthe dye radical; X represents a sulfonyl group, a carbonyl group or asingle chemical bond; BALL represents a ballasting photographicallyinert radical rendering the dye-giving compound resistant to diffusion;and DYE represents a dye radical either on its own or together with R4.